The present invention relates to a hand planer.
More particularly, it relates to a hand planer having a housing supporting a planer head rotatable by a motor, a fan blower connected with the motor for generating a flow of air for moving chips, a chip ejector to which the flow of air is guided via air guidance ducts, and a chip conveying duct through the planer chips exit.
A hand planer of the generic type is known from DE-OS 34 06 728. In this hand planer the chips are discharged from a chip discharge opening of a chip conveying duct by the pumping and sucking action of one or two streams of cooling air to two chip ejecting openings which can be opened alternately in an optional manner. The chip ejecting opening can be unblocked toward one side or the other transversely to the feed direction by a swivelable, flap-type valve. This hand planer has the disadvantage that the removal of chips via the cooling air flow at or in the chip conveying duct proceeds with inadequate efficiency, i.e. an excessive air flow rate is required for a small quantity of chips.
The known hand planer is described in two embodiment examples. In the embodiment example with only one cooling air flow, the conveying effect is fully effective only in a preferred direction, namely when the cooling air can flow substantially parallel to the flap-like valve toward the ejecting opening.
However, if the ejecting opening directed opposite to the preferred direction is preselected rather than the preferred direction, the cooling air flow rebounds off the flap-like valve virtually normally thereto and the velocity of the air flow, and accordingly the conveying effect, is reduced as a result of turbulence. The chip conveying duct can become stopped in this way.
In the embodiment example with two cooling air flows acting simultaneously at both sides of the chip discharge opening, the conveying effect is improved, but the turbulence is also increased in the region of the valve. Accordingly, the efficiency with which the chips are moved is still definitely reduced. This makes poor use of the available conveying capacity.
Further disadvantages of the hand planer include the relatively poor sealing effect of the valve and a constant, unintentional escape of chips from the ejecting opening which is closed per se, as well as the poor possibility of distinguishing the selected chip ejecting direction and the trouble-prone character of the expensively constructed valve bearing.